Genetic research on human epilepsy is advancing rapidly, with more than 20 genes already identified in rare Mendelian epilepsy syndromes, and major efforts underway to identify genes in the more common genetically complex epilepsies. Clinical genetic testing is available for several epilepsy syndromes in which genes have been identified, and clinicians who treat patients with epilepsy widely believe that genetic testing wil be helpful for their patients. However, almost no empirical data are available on the psychosocial impact of genetic information on people with epilepsy and their family members. Research in this area is urgently needed because of the significant psychosocial dimensions of living with epilepsy, which include stigma, discrimination, reduced rates of marriage and reproduction, and reduced health-related quality of life. This study will address this gap by researching psychosocial outcomes and their relations with genetic attributions and actual genetic test results in families containing multiple individuals with epilepsy. The study involves two parts. First, we will carry out a survey of 1053 individuals from 115 families, to evaluate stated preferences and anticipated benefits and harms of genetic testing, and measures of quality of life, epilepsy-related stigma, and their predictors. Second, we will offer clinical geneic testing to individuals in a subset of families (21 families, containing 195 individuals) with a for of temporal lobe epilepsy initially described by our group, autosomal dominant partial epilepsy with auditory features (ADPEAF). Half of these families were previously found to have mutations in the LGI1 gene on chromosome 10. Although study participants have been informed about this gene discovery in aggregate (through a newsletter), they have never been offered individual results. We recently established a clinical genetic test for LGI1 in our institution's Clinical Laboratory Improvement Act (CLIA)-certified laboratory, and we will we will offer clinical genetic testing to individuals in families with ADPEAF, evaluate actual uptake and its predictors, and follow prospectively the impact of genetic information on individuals who choose to be tested. We will also carry out qualitative interviews on a subset of individuals offered testing, t explore in greater depth the range of issues related to receiving genetic information in epilepsy. No previous quantitative study has investigated the psychosocial impact of genetic information on individuals with epilepsy and their family members; hence the results should be extremely valuable for planning of genetic services that maximize benefit and minimize harm in this disorder.